000 AGXX40 KNHC 290730 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 330 AM EDT MON AUG 29 2011 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... RECENT AND CURRENT BUOY OBSERVATIONS ALONG WITH A PARTIAL ASCAT PASS FROM 0230 UTC LAST NIGHT AGAIN REVEAL W-NW FLOW OVER MUCH OF THE AREA N OF 27N E 92W...WITH AVERAGE SPEEDS OF 10 KT. ELSEWHERE WINDS ARE SW-W 5-10 KT S OF 27N E OF 85W...NE-E 5-10 KT S OF 27N W OF 85W...AND S-SW 5-10 KT IN THE NW ZONE W OF 92W. OBSERVED SEAS THROUGHOUT ARE IN THE GENERAL RANGE OF 1-3 FT. THE PRELIMINARY 0600 UTC SYNOPTIC ANALYSIS HAS A RATHER WEAK PRES PATTERN OVER THE AREA. A WEAK COLD FRONT EXTENDS FROM THE FLORIDA BIG BEND REGION SW TO 27N88W...AND NORTHWESTWARD TO SW LOUISIANA. THE COLD FRONT WILL BECOME STALL AND DISSIPATE THROUGH TUE AS HIGH PRES BUILD WESTWARD TO THE N OF THE AREA THROUGH THU...THEN WEAKENS SOME FRI. AS A RESULT...WINDS WILL BECOME E-SE THROUGHOUT BEGINNING TUE AND INTO FRI. THE EXCEPTIONS WILL BE SEEN IN THE SW ZONE AND S OF ABOUT 26N IN THE MIDDLE ZONE WHERE A TIGHTER PRES GRADIENT BETWEEN EXPECTED BROAD LOW PRES IN THE SW GULF AND THE RIDGE SHOULD ALLOW FOR E-SE WINDS TO INCREASE TO 15-20 KT IN THOSE PORTIONS AS GFS AND ECMWF ARE NOW MORE IN AGREEMENT WITH THESE WINDS MATERIALIZING. AS IN PREVIOUS FORECAST THINKING...THE EXPECTED LOW PRES SHOULD EVOLVE FROM A WEAK LOW LEVEL FEATURE THAT SLOWLY MOVES WESTWARD ACROSS THE YUCATAN PENINSULA...AND EVENTUALLY COMES INTO FAVORABLE INTERACTION WITH AN UPPER LEVEL TROUGH THAT IS PRESENTLY OVER THE WESTERN GULF TO SPIN UP THE LOW IN THE EASTERN BAY OF CAMPECHE TONIGHT. GLOBAL MODELS TRACK THE LOW IN A GENERAL NW DIRECTION TOWARDS THE VICINITY OF MEXICO BY LATE WED. THE LATEST REGIONAL NAM GUIDANCE IS A LOT SLOWER KEEPING THE LOW IN THE NE PART OF THE SW ZONE THROUGH DAY 5 FT...AND AS A STRONGER SYSTEM. FOR THIS FORECAST PACKAGE I WILL GO WITH MODEL CONSENSUS WHILE MAINTAINING CONTINUITY WITH PREVIOUS FORECAST THINKING BY NOT DEVIATING FROM CURRENT FORECAST WINDS AND SEAS WITH LOW. LATEST NOAA WAVEWATCH GUIDANCE LOOKS REASONABLE WITH INITIAL SEA STATE VALUES...AND WILL CLOSELY LEAN TOWARDS ITS FORECAST GUIDANCE VALUES FOR THE NEXT NT4 ISSUANCE. SW ATLC S OF 31N W OF 55W... S-SW WINDS AND SEAS LEFT BEHIND FROM IRENE ARE CONTINUING TO DECREASE OVER THE FAR N CENTRAL AND NE PORTIONS OF THE AREA N OF 27N AS SUGGESTED BY AN ASCAT PASS FROM 0230 UTC LAST NIGHT...WITH THE WINDS NOW DOWN TO 10-15 KT AND SEAS IN THE 4-6 FT RANGE. ELSEWHERE WINDS ARE SE-S 10-15 KT E OF THE BAHAMAS ...EXCEPT E-SE 10-15 KT S OF 23N...AND S-SW 10-15 KT AND S OF 27N W OF THE BAHAMAS. SEAS ARE FORECAST TO SUBSIDE TO 2-4 FT...AND TO 1-2 FT W OF BAHAMAS BY WED. WINDS WILL BECOME RATHER LIGHT THROUGHOUT BEGINNING TUE. THE PRELIMINARY 0600 UTC ANALYSIS SHOWS A WEAK RIDGE STRETCHING FROM 2N65W TO EASTERN CUBA...WHILE A WEAK PRES PATTERN IS PRESENT ELSEWHERE. THE HIGH WILL LIFT NORTHWARD SOME THROUGH TUE NIGHT ...THEN WEAKEN AND RETREAT EASTWARD WED AND THU AS A WEAK COLD FRONT ENTERS INTO THE NW PORTION. THE FRONT WILL MOVE SLOWLY E ACROSS THE NORTHERN WATERS WED THROUGH FRI. WINDS MAY PERIODICALLY INCREASE TO 15-20 KT BETWEEN THE SE BAHAMAS...EASTERN CUBA AND HISPANIOLA TUE THROUGH WED. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W...PARTIAL ASCAT DATA FROM LATE LAST NIGHT ALONG WITH BUOY OBSERVATIONS SHOW MOSTLY LIGHT TO MODERATE E-SE WINDS THROUGHOUT...EXCEPT IN THE CARIBBEAN PORTION S OF 16N BETWEEN 72W AND 77W WHERE WINDS HAVE INCREASED TO 15-20 KT WITH SCATTERED TSTMS PRESENT THERE. WINDS ARE MAINLY NE-E 10 KT IN THE TROPICAL N ATLC ZONE. THE 15-20 KT WINDS IN THE CARIBBEAN S OF 14N BETWEEN 68W-72W ARE FORECAST TO EXPAND NORTHWESTWARD INTO THE NW CARIBBEAN SEA TUE THROUGH THU AS CENTRAL ATLC HIGH PRES BUILDS WESTWARD. THE COMBINATION OF THE HIGH AND LOWER PRESSURES OVER NW COLOMBIA WILL INDUCE A TIGHTER PRESSURE GRADIENT ALLOWING FOR THOSE WINDS TO INCREASE TO 15-20 KT. THE GRADIENT WEAKENS ON FRI ALLOWING FOR THESE WINDS TO DIMINISH OVER MUCH OF THE SW AND NW ZONES..BUT CONTINUE OVER THE SOUTHERN SECTION OF THE EASTERN CARIBBEAN. EXPECT SEAS TO BUILD TO 9 FT OVER THE MIDDLE PORTION OF THE CARIBBEAN N OF 11N BETWEEN 67W-80W TUE AND WED. WARNINGS... GULF OF MEXICO... .NONE. CARIBBEAN AND TROPICAL N ATLC... .NONE. SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE